Disazo dyestuffs and their chromium, iron and cobalt complexes



Patented Jan. 1, 1952 DISAZO DYESTUFFS AND THEIR CHRO- MIUM, IRON ANDCOBALT COMPLEXES :Walter Wehrli and Willy Steinemann, Basel,

- Switzerland, assignors to Sandoz A. G., Basel,

Switzerland, a Swissfirm g No Drawing; Application March 20, 1950,Serial No. 150,797. In Switzerland April 14, 1949 I The presentinvention relates to new disazo dyestuffs and their chromium, iron andcobalt complexes which are particularly suitable fordyeing leather, andto the production thereof.

' According to the present invention, it has been found that valuabledisazo dyestufis can be obtained by startingfrom 1' mol of ano-aminophenol or of an o-aminonaphthol, 1 mol of a 1- amino -8hydroxynaphthalene sulphonic acid and 1 mol of a naphthol capable ofcoupling and which may also be sulphonated, and building up in this waydisazo dyestufis'of the formula on N='N 1 -z'= H I 7 t, N=N

wherein denotes the residue of an o-hydroxy diazo com.- pound of thebenzene or naphthalene series which may it desired also be furthersubstituted, and

2 denotes the residue of a naphthol which may be sulphonated and whichis capable of coupling in the o-position to the OH group, and in whichR1 and R2 together must contain at least one sulphonic acid group, andone Z denotes a sulphonic acid group and the other Z denotes a sulphonicacid group or a hydrogen atom. 1

For the purpose of converting these new dyestufis into compoundscontaining chromium, iron or cobalt bound in a complex form, the disazodyestuffs so obtained, or the monoazo dyestuffs intermediately'obtainedduring their preparation, are treated with reagents capable of yielding.chromium, iron andcobalt respectively.

As reagents capable of yielding chromium, iron and cobalt, respectivelyuse may be made of: potassium chrome alum, ammonium chrome alum,

sodium chrome'alum, chromium chloride, chromium sulphate, chromiumacetate, chromium formiate, cobalt acetate, cobalt formiate, cobaltchloride, cobalt sulphate, iron sulphate, iron chloride. j

4s starting'materialathere may be employed as- -aminophenol oro-aminonaphthol for instance the following substances? 4-nitro-.

counts. (01. 260-148) aminophenol, 5-nitro-2-aminophenol, 4-chloro-2-aminophenol, 6-nitro'4-chloro-2-aminophenol,6-nitro-2-aminophenol-l-sulphonic acid, 4-nitro-2-aminophenol-6-sulphonic acid,1-amino-2-hydroxynaphthalene-4-sulphonic' acid, l-amino-Z-hydroxy-6-nitronaphthalene 4 sulphonic acid,

and 2-aminophenol-4.6-disulphonic acid; as 1- amino 8 hydroxynaphthalenesulphonic acids there may for example be used:l-amino-B-hydroxynaphthalene-3.6-disulphonic acid, l-amino-8-hydroxynaphthalene-4-sulphonic acid, and 1- amino 3hydroxynaphthalene-4.6-disulphonic acid; and asnaphthols capable ofcoupling and which may be sulphonated, there may for example beutilized: "beta naphtholf ,2-hydroxynaphthalene-S-sulphonic acid,2;-hydroxynaphthalenei-sulphonic acid, l-hydroxynaphthalene- 4-sulphonicacid, 1-hydroxynaphthalene-3-sulphonic acid,1-hydroxynaphthalene-5-sulphonic acid,1-hydroxynaphthalene-3.6-disu1phonic acid,1-hydroxynaphthalene-3.8-disulphonic acid, 1-hydroxynaphthalene-4.8-disulphonic acid,2-hydroxynaphthalene-S.fi-disulphonic acid, and 1.8-dihydroxynaphthalene-3.6-disulphonic acid.

It will be understood that in the examples the specifically mentionedmetal yielding agent may be replaced by any one of the aforementionedagents to yield the corresponding metal complex.

The new dyestuffs are very soluble in water and dye leather in excellentgray shades which are fast to light.

The following examples illustrate the invention without limiting it inany way. The parts denote parts by weight. The temperatures are indegrees centigrade.

Example 1 23.4 parts of 4-nitro-2-aminophenol-6-sul phonic acid arediazotized in the usual way and coupled in an ice cold solution madestrongly alkaline with sodium carbonate with 31.9 parts oflene-.3,6-disulphonic acid are diazotized with so- 3, dium nitritecoupled with 22.4 parts of Z-hydroxynaphthalene-fi-sulphonic acid andthen the monoazo dyestufi. which is formed is saponified with analkaline reagent and finally coupled with the diazo compound from 23.4parts of i-nitro- 2-aminophenola6;sulphonic acid.

For conversion into the cobalt complex, the disazo dyestuii is warmedfor several hours at 90-95 with an aqueous solution containing 30' partsof cobalt sulphate in the 'rDI'BSGl'lCBOf: SQ?- dium acetate. Thereuponthermetahcontain-ing, dyestufi is separated in known manner. It dyesleather in gray shades of excellent'fastnesswm light.

Erample 2 23.4 parts of 6-nitro-2 aminophenol+4-sule phonic acid arediazotized with 6.9parts of sodium nitrite and coupled in the presenceof'an excess of sodium carbonate with 31.9 parts of1-amino-8-h-ydroxynaphthalene 1:3.6 disulphcnic; acid; The. aminoazo-.dyestuff is iisolatedcby salt-.- ing; out and: .filteringgoff; and. isthereuponadisa solved? again,- and .aftenthe addition ch69; arts:=Off'1SOdium nitrite; is further.v diazotizedy-by; pour-r ing into amixture of. diluteehydrochloricacid=andc ice. It is; finally;ceuplediwith- 14-.4uparts :of;v fl-naphthol in alkaline solution.

The: disazo' .dyestufi thusfi'obtained and. which.

corresponds-to:theformulaz is converted into 1 its metal complexeby'warmingi for 'severarhours at: 90 95-in a: solution: con:- tainingsodium 1 acetate and 3i? "par-ts: :of I: cobalt:- sulphate; Theisolated"dyestufi which contains: cobalt incomplexform dyes zleatherrin. gray shades of excell'entfastness torlightr" Example 3."

18.9 parts of 2'-aminophenol-4-sulphonic acid are diazotized with dilutesulphuricacid and 6.9 parts of sodium nitrite and coupled with 31.9parts of 1-amino-8 hydroxynaphthalene-3.S disulphonic acid in an icecold solution made strongly alkaline with sodium carbonate. When thecoupling'is finished, the aminoazo dyestuff which is formed is isolatedand is dissolved water and then coupled by adding: 6.9 parts of sodiumnitrite and allowing'themixturetorun slowly into a mixtureof-dilute-sulphuric acid and 4 ice. It is then coupled with 22.4 partsof L -hydroxynaphthalene-5-sulphonic acid in the presence of sodiumcarbonate. The disazo dyestuff is isolated in the usual manner and iswarmed for several hours at -95 in an aqueous solution,.of j301-part5?of cobalt-. sulphate containing sodium acetate in the solution. Thedyestufi contains cobalt bound in complex form and dyes leather in grayshades of excellent fastness to lights Example 5 1524 parts of4=nitro=2-aminophenol are diazotized in the usuakway and coupled with31.9 parts of-1-amino-8- hydroxynaphthalene 3.6-disulphonicpacidainagsclution containing an excess ofitsodiumicarbonate. The monoazodyestuff is salted out, filtered OE and again dissolved in water and-isthen treated with 6.9 parts of sodium nitrite and poured slowly into icecold dilute hydrochloric acid? Whenthe xdiazotiz'ationds complete' it iscoupledwith" a solution of 2 113; droxynaphthalene 6=sulphonic acid madealka-- line with sodium carbonate. 'I'heproduct is com-'- verted" intoits-cobalt complex: by 'warming for several hours at 90 with an aqueoussolution containing sodium acetate and 30 parts of cobalt sulphate Thecobaltcomplex of the disazo dye'-- stuff dyes" leatherin very 'good grayshades: of?

very goodiastness to light.

E ztampleafi 23.4 parts of 6-nitro-2-aminopheno1-4-sulionic acid arediazotizedtinthe'usual way and coupled in the presence of anlexcess ofsodium carbonate with 31.9 parts of1-a.mino-8+hydroxy-naphthalene-3.6-disulfonic acid. The producedaminoazo dyestuff is isolated, again diazotized, and

finally coupled with=-14;5"'parts of Z-hydroxynaphthalene. In order toconvert the thus-obtained disazo dyestuif into the iron complex: itisheated for several hours to 90-100 in an aqueous sodium acetate solutioncontaining 30 parts of ferrous sulfate. The iron-containing dyestufi.

thus. produced dyes .leather in' brownishegray" shades of verygood'fastnesstotlighfij Example 7 The aminoazo dyestufffobtained by thesodaalkaline couplinggoft. 23.4 1parts ioi diazotizedA-mnitror2eaminophenol-r6-sulionic: acid: and: 31;9.- parts of;1-amino-8-hydroxynaphthalenee3.fi-die sulfonic. acid, 1 is; againdiazotized and thereupon coupled: with.,22.4. partseof Schdifers salt.The resultant. disazo dyestufi' corresponds-to .the .for-.-=

mula:

In order-to convert it into the chromium'com plex, it isboiled forseveral hours; under arefliix" condenser; in'1000 parts of "Water with40 parts of chromium fluoride in the presence of sodium acetate, and theformed complex is then isolated? The. tli'us obtainedchromium-containing dyestufi dyes leather-"in beautiful neutral" grayshades of 1 excellent fastne'sstolight.

The disazo dyestuff described in Example 3, obtained from 23.4 parts of4-nitro-2-aminophenol-G-sulfonic acid, 31.9 parts of 1-amino-8-hydroxynaphthalene-4.6-disulfonic acid and 22.4

Other valuable'disazo' dyestufls and their chr'omium, iron and cobaltcomplexes can be'obtained according to the present invention for examplefrom corresponding amounts of the following components, while otherwiseproceeding according to the preceding examples:

Shade ofthe o-Ammophenol l-amino-fi-hydroxy-naphtha- Naphthols oapabMeta1 dyeing of the o Aminonapmho1 lene-sulphomc aclds of couplingcomplex meflilzllgggfigex l 4-nitro-2-aminopheno1-6-su1-l-amino-S-hydroxy-naph- 1-hydro xy napha1ene-4- ,,-Coba1t-. Gray.; 1

phonic acid. thad1ene-3.6-disu1phon1c sulphonic acid; 1 col. 2 do do2-hydroxy-naphthalene-4- do Do.

sulphonicacid. 4-ch1or-2-aminophenol-6- do 2-hydroxy-naphthalene-6- doDo. sulphonic acid. sulphomc acid. l-amino-Z-hydroxynaphdo .do doBrowmsh-gray.

thalenel-sulphonic acid. 4-chlor-6-nitro-2-aminodo ..do do Do. V phenol.t v 4-nitro-2-aminophenol. do 1.8-d1hydroxy-naphtha1cnedo....Reddish-gray.

' 3.6d sulphomc acid. 4-nitro-2-aminophenoI-6- 1-amino-8-hydroxy-naph-2-hydroxy-naph-thalene-6- do. Gray. sulphonic acid.thalenei-sulphonicacld. sulphonic acid. 1-amino-2-hydroxy-naph-'l-arnino-s'hydroxy-naphdc do Do.

thalene-i-sulphonic acid. thalcne-4.6-d1sulpnic acld. 9 do dol-hydroxy-naphthalenci- .do Do.

sulphonicacid. 10... 6-nitro-2-aminopheno1-4- dn 3-naphthol .do.; Do.-

sulphonic acid.

Parts of 2-hydroxynaphthalene-6-su1fonic acid is boiled under a refluxcondenser for several hours in an aqueous solution of sodium acetatecontaining parts of chromium fluoride, in order to convert the dyestuffto the chromium complex. The obtained and isolated chromium-containingdyestufi dyes leather in gray shades of very good fastness to light.

Example 9 The disazo dyestufi obtained according to Example 1 from 23.4parts of 4-nitro-2-aminophenol-fi-sulfonic acid, 31.9 parts of1-amino-8-hydroxynaphthalene-3.fi-disulfonic acid and 22.4 parts of2-hydroxynaphthalene-6-sulfonic acid is boiled under a reflux condenserfor several hours in an aqueous sodium acetate solution containing 30parts of ferrous sulfate. The isolated resultant dyestuff, containingiron bound in complex form, dyes leather in brownish gray shades ofoutstanding fastness to light.

Example 10 Example 11 The-disazo dyestuff obtained according to Example10 from 23.4 parts of 4-nitro-2-aminophenol-G-sulfonic acid, 23.9 partsof 1-amino-8- hydroxynaphthalene-4-su1fonic acid and 22.4 parts of2-hydroxynaphthalene-fi-sulfonic acid, is boiled for several hours undera reflux condenser in 1000 parts of water with parts of Ychromiumfluoride in the presence of sodium acetate. The isolateddyestuff, containing chromium bound in complex form, dyes leather ingray, shades of very good fastness to light.

The metal-free disazo dyestuff corresponding to item 1 of the foregoingtable corresponds to the formula:

HOaS- =N- HOaS Having thus disclosed our invention what we claim is:

l. A metal complex compound selected from the group consisting of thechromium, iron and cobalt complex compounds of the disazo dyestuffscorresponding to the formula Ho N=N on on I wherein R1 stands for arylradical selected from the group consisting of radicals of the benzeneand naphthalene series, the OH attached to R1 being in ortho-position tothe adjacent azo bridge, wherein R2 stands for a radical of thenaphthalene series, the OH attached to R2 being in ortho-position to theadjacent azo bridge, wherein one y and one Z each stand for a sulfonicacid group, the other y and Z being each a member chosen irom'the groupconsisting of hydrogen and the sulfonic acid group.

2. The cobalt complex compound of the disazo dyestufl of the formulaoiN- N=N HOaS SOaH 4. The cobalt complex compoundreoijthe disazodyestufi oi the formula 5. The chromium complex compound of the disazodyestuff of the formula 6. The iron complexzompound of the disazodyestufi of the formula.

WALTER WEI-IRLI. WILLY: STEINEMAN N.

REFERENCES} CITED The following references are of record in the file,.of this patent UNITEDv STATES" PATENTS Name Date JuIiu's Feb. 27, 1900Number

6. THE IRON COMPLEX COMPOUND OF THE DISAZO DYESTUFF OF THE FORMULA